#include<bits/stdc++.h>
using namespace std;
#define int long long

signed main(){
	string a, b;
	cin>>a>>b;
	
	reverse(a.begin(), a.end());
	reverse(b.begin(), b.end());
	
	if(a.size() < b.size())
		swap(a, b);
	
	for(int i = 0;i < b.size();i++){
		if(a[i] == b[i]){
			a[i] = '0';
		}
		else{
			a[i] = '1';
		}
	}
	reverse(a.begin(), a.end());
	int idx;
	for(int i = 0;i < a.size();i++){
		if(a[i] != '0'){
			idx = i;
			break;
		}
	}
	for(int i = idx;i < a.size();i++){
		cout<<a[i];
	}
}
